Earthquakes are more common in some parts of the world than others, because some places, like California, sit on top of the meeting point, or fault, of two plates. ... When those plates scrape against each other and cause an earthquake, the results can be deadly and devastating. And then Tsunamis occur most often in the Pacific Ocean and Indonesia because the Pacific Rim bordering the Ocean has a large number of active submarine earthquake zones. However, tsunamis have also occurred recently in the Mediterranean Sea region and are expected in the Caribbean Sea as well.